Easiest way for money is to buy the Auto hit thing and then the first lvl of animals lair you just leave the weapon on the middle of the lair and mushies
Seriosly i got trough the red door and i was all like hey wait i wanna go trought the other door! but no they kick you in tha ass and close the door and let's a zombie do the work for them i was like HEY! Fack you biatches i'm getting outta here but no a zombie kills me ._. i expressed my feelings about the game happy?